不同程度干旱胁迫对马铃薯幼苗生长和生理特性的影响

Effects of Different Drought Treatments on Growth Indicators and Physiological Characters of Potato Seedlings

试验以马铃薯品种美康1号原种一代为材料,用盆栽方法人工模拟土壤干旱条件,设置土壤田间最大持水量的80%、60%、40%和20%4个水分处理水平,研究了不同程度干旱胁迫对马铃薯幼苗生长和生理特性的影响,结果表明:苗期土壤含水量为田间最大持水量80%(CK)时,株高、茎粗、单株叶面积、地上部鲜重均最大,随土壤含水量的降低和时间的延长各生长参数的增幅逐渐降低;可溶性糖(SS)和丙二醛(MDA)含量随土壤含水量的降低和时间的延长呈逐渐增加的趋势;氧化物歧化酶(SOD)和过氧化物酶(POD)在轻度胁迫下持续上升,而在中度和重度胁迫下呈现先升高后降低的趋势,并且在胁迫12 d后超氧化物歧化酶(SOD)低于同期对照。表明马铃薯幼苗可通过形态适应和生理适应提高抗旱性,具有一定的抗旱能力。

The seedlings of ＇Meikang 1＇ were grown under the water supply regimes of 80%, 60%, 40%, and 20% water-holding capacity, respectively, in an open-side greenhouse in order to understand the effect of different drought treatments on growth indicators and physiological characters of potato seedlings. The results showed that the stem length, stem diameter, leaf area of seedling and shoot fresh weight were the greatest in the seedling under the treatment of 80% water-holding capacity, however the growth rate of these growth parameters gradually declined in 60%-20% water-holding capacity with the prolonged stress period. The content of soluble sugar （SS） and malondialdehyde （MDA） rapidly increased with the aggravation of water stress and prolonged stress period. The activities of superoxide dismutase （SOD） and the peroxidase （POD） were increased continuously under light drought stress, and these were increased at the beginning and then were dropped under middle and serious drought stresses. The results indicated that potato seedlings could tolerate drought stress by means of morphological adaptations and physiological adaptation, and have drought resistance capability to some extent.